Vin makes a fake escape attempt using screws from her cot as a distraction, but Yomen easily subdues her by using atium to predict her moves. It confirms that he is at least capable of burning atium, though he still denies being a Mistborn. During their subsequent conversation, Yomen tells Vin that he believes that the Lord Ruler is still alive. He argues that Vin’s defeat of the Lord Ruler was orchestrated by the Lord Ruler himself. He explains that this is why he’s keeping Vin alive, as he believes that killing her might interfere with his god’s plan. When he questions Vin’s motivation for conquering the city, she says they’re there for the atium, which he declares worthless in a world where there are no noble houses left to desire it. Still convinced that the Lord Ruler has a plan, Yomen orders his guards to return Vin to her cell.

Elend returns to his camp with the new koloss, bringing the total number under his command to thirty-seven thousand. Ham greets Elend, and Elend confirms to Ham that Vin is still alive because the koloss he bonded to her are still under control. Ham then tells him that scouts from the Central Dominance have reported starvation and mass migrations as lava from the Ashmounts has destroyed some areas entirely, and the entire Southern Dominance is burning. Though still unsure whether the mist spirit’s warning against attacking Fadrex was genuine, Elend concludes that he cannot afford to wait and orders Ham to attack the city at dawn, using the koloss for the first assault.

Sazed watches over Spook, who is still unconscious and seriously injured. Beldre says that Spook has become a hero to the people of Urteau, and that he got her brother to soften his stance. She remains devoted to Spook, sitting by his side every day, which Sazed finds both touching and surprising given how briefly they knew each other.

Sazed retreats to his quarters and finishes reviewing the last of his religious texts, only to conclude that none hold the truth he seeks. When he opens the journal in which he and Tindwyl put all their notes, he finds Mare’s drawing of the flower and feels betrayed over his continued lack of faith. He overhears Breeze and TenSoon talking in the hallway. When TenSoon refers to Sazed as “the Announcer,” Sazed rushes out to get him to repeat what he said. When he does, and Sazed checks his notes, he finds that Ruin has altered them to call him the “Holy First Witness” instead. When he questions TenSoon on how he knows the right term, the kandra reveals that the First Generation of kandra are the original Terris packmen who accompanied Rashek, who later became the Lord Ruler, to the Well of Ascension. TenSoon explains that rather than kill his friends, who posed a threat to his rule, Rashek transformed them into the first kandra, granting them immortality at the cost of their humanity. Sazed realizes that the ancient Terris religion is not lost, but instead lives on in the minds of the First Generation. Realizing that there is still something worth pursuing, Sazed hastily packs to follow TenSoon to the kandra Homeland.

Ruin, still appearing as Reen, rambles to Vin, and she listens, hoping to find a clue to stop it. It attributes much of the chaos in the world to the actions of the Lord Ruler, who tried to preserve the world but ultimately caused more damage. Vin realizes that the power at the Well of Ascension must regenerate every thousand years, but she still cannot grasp why Ruin needed her specifically to free it.

Vin calls for Yomen and convinces him to meet with her by offering to share information. He asks how Elend controls the koloss, and she explains that he uses duralumin and emotional Allomancy. She also plays along with his insistence about the Lord Ruler’s plans, saying that he’d planned for them to meet. When Yomen brings her maps to mark the other caches, she notices that their locations are linked to existing metal deposits. She first realizes that the metal around the caches, and the metal of the plaques themselves, protected them from Ruin, then that Ruin had manipulated her into finding the atium cache for it.

An Inquisitor enters the chamber: Marsh. He informs Yomen that Elend’s army is preparing to attack. He also demands the atium cache, only for Yomen to admit that his supposed store of the metal was just a ruse to deceive Vin. Marsh’s unemotional statement that the Lord Ruler is dead shakes Yomen, and Vin tries to use this to her advantage to get him on her side. She insists that Elend won’t attack, but Marsh counters that Elend will kill for her as she once killed for him.

In a dream, Spook is told to send an urgent message to Vin that the force she released from the Well of Ascension had been controlling both him and Quellion. When he finally awakens, immobilized in bandages, Breeze, Beldre, and Goradel are there. They explain that Sazed left with TenSoon. Spook, remembering his dream, insists on sending his message to Vin. Goradel volunteers to deliver it, and Spook instructs him to bring a thin sheet of steel to engrave it on, as it is not safe to say aloud and he cannot risk it being manipulated.

Despite knowing the strategic advantage of using the koloss to overwhelm Fadrex’s defenses, Elend is uneasy about unleashing the creatures due to the potential for collateral damage. After discussing it with Ham, Elend ultimately decides not to attack.

Inside Fadrex, Vin sees that Elend’s decision to retreat has confused Ruin. She uses the moment to challenge Ruin’s supposed omniscience, telling him she knows he’s been manipulating her to search for the atium. Marsh orders Yomen to tell his men to attack Elend’s army, promising that the Lord Ruler will protect Yomen’s men. Elend soon realizes it’s a distraction and orders his forces to retreat. Ruin then takes back control of the horde, which begins to massacre the soldiers.

Ruin uses Marsh to try to force Vin to reveal the location of the atium cache, but she manages to steal a vial of metals from the Inquisitor. She wounds him using her earring and secretly commands her small group of koloss, led by Human, to attack Yomen’s army. Using this as proof that Marsh lied, she gets Yomen on her side. He orders his forces to retreat into the city and to allow Elend’s in as well. When Marsh recovers and attacks her, Vin instinctively draws on the power of the mists to repel him, forcing him to flee. Vin then goes to Elend and tells him that Yomen will let them take refuge within the city. She takes over dealing with the koloss while Elend coordinates the retreat.

Sazed travels with TenSoon to the kandra Homeland, with the kandra explaining more about his people’s origins on the way. The Lord Ruler turned the original Feruchemists into mistwraiths, which can then become the kandra with Hemalurgic spikes, which they call the Blessings. The kandra have greater independence than the koloss and Inquisitors, making them less susceptible to Ruin’s control. TenSoon tells him they don’t have much time left, and they need to be ready for when the Hero of Ages leads an army of Allomancers to the Homeland. He tells Sazed that he needs his help to convince the kandra to prepare as well. Eventually, they reach the Pits of Hathsin, beneath which is the kandra Homeland.

After saying goodbye to TenSoon, Sazed journeys into the tunnels and meets two kandra guards, who are surprised to see a human. Sazed tells them that he has come to speak with the First Generation. After he implies that he will reveal the location of the Homeland if turned away, the guards escort him inside.

Vin and Elend stand atop the fortifications of Fadrex, watching the growing army of koloss amassing outside. Yomen questions why the koloss have not attacked, and Vin says it’s an intimidation tactic. Privately, she thinks that Ruin is waiting until he learns where the atium is hidden. A massive earthquake suddenly hits the city, toppling buildings and even crushing some koloss. Despite the damage, Elend urges Yomen to hold onto hope. As they discuss their next move, Vin forms a plan to force Ruin’s hand by putting herself in a situation of extreme danger, as the mists only come to her aid in moments of intense desperation. To hide her intentions from Ruin, Vin tells Elend that she needs to leave to retrieve the atium, suggesting that bringing it to Fadrex might protect it better. Although Elend is confused, he chooses to trust Vin and says nothing. They embrace, and Vin sets off alone for Luthadel.

Sazed arrives at the Homeland, marveling at the intricate and varied forms of the kandra, who watch him with fear and curiosity. The guards lead him to Trustwarren, where the Second Generation of kandra question his presence. Sazed says he is the Announcer, sent to reveal the Hero of Ages, and warns them that the world is ending. KanPaar asks Sazed if TenSoon sent him and, when he confirms, asks what he thinks will change their minds. Sazed replies that, as the Terris religion is the only ancient faith to survive, its prophecies hold significant truth. If they compare his corrupted records with the kandra’s original truths, they might uncover Ruin’s plans. The First Generation finally appear, still wearing their own bones. Calling Sazed a Worldbringer, they tell the other kandra to leave so they can speak to him alone.

Marsh kneels in the ash as Ruin keeps him dormant, waiting for orders. Suddenly, Ruin commands him to move. He directs Marsh to a lone traveler struggling through the ash: Goradel. The man attempts to defend himself, but Marsh quickly overpowers him and kills both Goradel and his horse. As Goradel dies, he tries to destroy the metal sheet he’s carrying, but Marsh, driven by Ruin, retrieves it.

When he realizes that Ruin cannot read the message on the metal, Marsh reads it aloud. It’s a letter from Spook to Vin, warning her about Ruin’s influence through small metal piercings and advising her not to trust anyone pierced by metal. After reading the message, Ruin forces Marsh to destroy it and sends him toward Luthadel.

Elend and Yomen walk through Fadrex, discussing the city’s defense. They visit the infirmary, where Elend, still guilty over not foreseeing Ruin’s ability to reclaim the koloss, offers encouragement to the wounded soldiers. A woman arrives with her son, who is suffering from violent seizures after being exposed to the mists. When Elend mentions that the illness affects precisely 16% of people, Yomen mentions that the number 16 is sacred in Church doctrine. Elend hypothesizes that the mistsickness is actually Snapping people, or awakening their latent Allomantic powers. To test his theory, Elend gives a metal vial to a soldier who had been stricken by the mists, and the man unexpectedly burns the metal, proving that he has become an Allomancer. Realizing that the mists are actually empowering people to fight, Elend orders Yomen to gather metal powders to distribute to anyone who has previously fallen sick. A soldier then bursts in, reporting that the koloss are attacking, forcing Elend to rush to the front lines.

Sazed speaks with the First Generation, trying to piece together the truth about the Hero of Ages prophecy. He learns that while Ruin did manipulate the prophecy, Vin still fits the description of the Hero. The leader of the First Generation, Haddek, says that the ancient Terris religion spoke of two opposing forces: Preservation and Ruin, who created the world together. Preservation sacrificed himself to imprison Ruin, and the power at the Well of Ascension was a remnant of Preservation’s essence. The kandra’s purpose, as given by the Lord Ruler, was to gather and protect Ruin’s power. The atium, gathered as part of the kandra’s Contracts, was never dispersed as the world believed. Instead, it was collected and stored.

TenSoon, meanwhile, discovers that Tyrian, the Ashmount closest to Luthadel, has erupted and left the surrounding plains flooded with lava, blocking his way to Fadrex.